1. Field of the Invention
This invention relates to an automotive passenger restraint and protection apparatus for automotive vehicles such as automobiles, which uses an electric retractor for retracting and protracting a seatbelt for protection of an occupant (driver or passenger), and also relates to a seatbelt retraction and protraction amount-detecting device.
2. Prior Art
Conventional automotive passenger restraint and protection apparatuses are operable upon a large deceleration of the automotive vehicle such as a collision to restrain an occupant by means of a seatbelt to prevent him from being thrown out of his seat and hence protect him from danger.
The conventional automotive restraint and protection apparatuses include a type provided with a seatbelt retractor for retracting or winding a seatbelt. The seatbelt retractor is generally provided with bias force-imparting means such as a spiral spring which always biases a reel shaft (takeup shaft) on which the seatbelt is wound, in a retracting or winding direction. The seatbelt is wound up on the reel shaft due to the bias force given by the bias force-imparting means when it is not mounted on the occupant, and it is protracted or withdrawn against the bias force to fasten or restrain the occupant when it is mounted on the occupant.
The seatbelt retractor is provided with emergency locking means which is normally actuated upon a large deceleration of the vehicle as mentioned above, to impede rotation of the reel shaft in the seatbelt protracting direction, so as for the seatbelt to surely restrain and protect the occupant.
According to the conventional automotive passenger restraint and protection apparatus, however, to mount the seatbelt onto the occupant, he has to protract the seatbelt against the bias force of the bias force-imparting means, which requires the occupant to exert some force to protract the seatbelt. As a result, a weak occupant who has degraded physical ability such as an advanced-age occupant takes long to mount the seatbelt onto his body.
Further, there can be a case that the occupant feels uneasy while he wears the seatbelt since he feels a sense of oppression owing to the bias force of the bias force-imparting means.
Moreover, the conventional automotive passenger restraint and protection apparatus is not provided with means for warning the occupant of danger to be caused by a doze and a collision.
A further disadvantage with the conventional apparatus is that an alien substance can become attached to the seatbelt after a long term use, which causes an increased friction between the seatbelt and a through anchor associated therewith, leading to insufficient retraction of the seatbelt.
The conventional automotive passenger restraint and protection apparatus has another disadvantage that when the occupant has protracted the seatbelt without the intention of wearing the same, it can happen that the seatbelt cannot be retracted until a certain time period elapses. Thus, the seatbelt cannot be quickly retracted against the occupant""s desire.
Further, in the conventional automotive passenger restraint and protection apparatus, in retracting the seatbelt into its extreme retracted position, if the occupant intentionally stops the seatbelt at a position apart from his body and then judges that the seatbelt has reached its extreme retracted position, the seatbelt can be set in position in an abnormally loosened state.
Further, in the conventional automotive passenger restraint and protection apparatus, when the occupant looks back for parking the vehicle while moving his body to protract the seatbelt, the seatbelt is wound back or retracted into the extreme re tracted position after the completion of protraction of the seatbelt, which gives a feeling of unnaturalness to the occupant.
Furthermore, when the occupant""s-body is not in a proper position for driving the vehicle, that is, his body is not facing forwardly of the vehicle, the seatbelt can be wound up into the extreme retracted position, based upon which position the occupant is given a predetermined amount of looseness of the seatbelt, which can result in an inappropriate amount of looseness of the seatbelt being given to the occupant to make him feel uncomfortable.
In the conventional passenger restraint and protection apparatus, in the event that the seatbelt becomes locked when a motor for driving the seatbelt is rotated in the direction of the seatbelt being protracted, no force is acted upon the seatbelt to retract the same, so that the seatbelt is kept in the locked state, which can make it impossible to protract the seatbelt unless a condition is newly set for the seatbelt to be retracted.
The condition for the seatbelt to be retracted is set in the cases where the vehicle is suddenly braked, the seatbelt is taken off or disconnected from the occupant""s body, and it is judged that the occupant""s vehicle is about to collide with some object, by a collision prediction system, for example.
FIG. 83 is a timing chart showing another example of the relationship between driving forces of a reel shaft for retracting and protracting a seatbelt onto and from the reel shaft, an urging force which the occupant receives from the seatbelt, and the seatbelt retracting and protracting speeds of the reel shaft in the conventional automotive passenger restraint and protection apparatus.
First, when attaching of the seatbelt to the occupant""s body is detected, retraction of the seatbelt onto the reel shaft is started by the reel shaft with a constant seatbelt retraction driving force, and this retraction is continued until the retraction of the seatbelt reaches its limit (time period t20). During this retraction, the urging force which the occupant receives from the seatbelt gradually increases while the retracting speed of the seatbelt onto the reel shaft gradually decreases.
Thereafter, when the retraction of the seatbelt has reached its limit (time point c), the retraction of the seatbelt by the reel shaft is stopped, and then protraction of the seatbelt can be effected due to a restitution force against the bias force of the spiral spring, etc., that is, a restitution force of the occupant""s body and clothes urged by the seatbelt. During this protraction, the acceleration of protraction of the seatbelt from the reel shaft increases.
Since when the retraction of the seatbelt by the reel shaft reaches its limit after the attaching of the seatbelt and the retracting motion stops, however, the seatbelt is suddenly returned in the direction in which the urging force is weakened due to the restitution force of the occupant""s body and clothes urged by the seatbelt, the acceleration of protraction of the seatbelt from the reel shaft suddenly increases and can exceed a threshold value required for locking the protracting motion of the seatbelt, so that the protracting motion of the seatbelt can be locked by a seatbelt locking mechanism. As a result, the urging force that the occupant receives from the seatbelt cannot be relieved after a time point when it assumes a large value (time point d) (time period t21).
An automotive passenger restraint and protection apparatus is also already known, which is provided with an airbag device for restraining an occupant through expansion of an airbag, a belt pretentioner for restraining the occupant by suddenly retracting a seatbelt, an airbag and pretensioner controller for controlling actuation time and expansion pressure of the airbag and actuation time and seatbelt-pulling force of the pretensioner, and a sensor for detecting negative acceleration acted upon the occupant upon a collision of the automotive vehicle.
When negative acceleration acted upon the occupant is detected by the sensor upon a collision of the automotive vehicle, a signal indicative of the negative acceleration from the sensor is-delivered to the airbag and pretensioner controller, which in turn controls the actuation time and expansion pressure of the airbag and actuation time and seatbelt-winding force of the pretensioner, whereby the airbag and the pretensioner are actuated.
In the known automotive passenger restraint and protection apparatus, however, the actuation time and expansion pressure of the airbag are controlled by the airbag and pretensioner controller upon a collision of the automotive vehicle, irrespective of the protracting speed of the seatbelt. Consequently, for example, when it is judged by the controller that the actuation times for actuating the airbag and the pretensioner should be set to longer values, the airbag and the pretensioner are actuated with the longer actuation times even in the event that the protracting speed of the seatbelt is so high that the occupant can collide against equipment within the compartment.
Further, when it is judged by the controller that the expansion pressure for actuating the airbag should be set to a higher value, the expansion pressure of the airbag cannot be changed according to the protracting speed of the airbag even in the event that the protracting speed of the seatbelt is so high and the occupant is restrained by the airbag expanded under such a higher expansion pressure that the occupant can directly receive a large impact applied to the vehicle.
Also, conventionally there is known a mechanism called xe2x80x9cEA mechanismxe2x80x9d (load limiter) which has a function of causing the reel shaft to rotate in the direction of protracting the seatbelt when a tension in excess of a prescribed value is applied to the seatbelt immediately after a collision of the automotive vehicle, so,as to control the tension to or below the prescribed value (hereinafter referred to as xe2x80x9cthe EA functionxe2x80x9d). The EA function is terminated when the seatbelt is protracted by a certain length after the EA function is made effective. That is, the EA function is carried out irrespective of the degree of magnitude of collision of the automotive vehicle. Consequently, in the event of a strong collision of the automotive vehicle, for example, the EA function can be terminated even at a time point when it is desired that the same function should be still exhibited, whereby a sudden impact can be applied to the occupant after termination of the EA function, which can result in insufficient effective absorption of an impact acted upon the occupant. On the other hand, in the event of a weak collision of the automotive vehicle, a tensile strength in excess of the prescribed value is not applied to the seatbelt, so that the EA function is not made effective, whereby impact absorption cannot be obtained.
Fault diagnosis of the seatbelt locking mechanism has conventionally been carried out through a determination by the occupant or the like as to whether the seatbelt can be actually retracted and protracted, or as to whether the seatbelt can be locked in position by suddenly protracting the same.
This manner of fault diagnosis, however, cannot always achieve accurate fault determination of the seatbelt locking mechanism.
Further, in the conventional automotive passenger restraint and protection apparatus, when the occupant with the seatbelt not mounted on his body pulls out the seatbelt without the intention of attaching the same to his body, immediately then gets off the vehicle and closes the door, the seatbelt is not retracted within a short time period, so that the seatbelt can be caught in the door to be damaged. Also, when during parking of the automotive vehicle, the seatbelt is pulled out and attached to a baggage or the like (into the mounted state of the seatbelt) and then, in this state the door is closed, the seatbelt can be also caught in the door if the seatbelt is then unnecessarily loosened.
An automotive passenger restraint and protection apparatus is also already known, which detects a possibility of collision of the automotive vehicle based upon the distance between the occupant""s vehicle and a preceding vehicle, and gives an alarm to alert the occupant to the danger of collision based upon the detection result, so as to prevent a traffic accident.
An example of the apparatus having such a warning function is disclosed by Japanese Laid-Open Utility Model Publication (Kokai) No. 6-71333, which is adapted to intermittently increase or decrease the fastening force of the seatbelt when it is detected that the distance between vehicles becomes shorter than a predetermined safety distance.
In the known automotive passenger restraint and protection apparatus, however, the control of intermittent increase or decrease of the fastening force is carried out in a monotonous manner irrespective of the degree of possibility of expected danger so long as the distance between vehicles is less than the safety distance. Consequently, when the degree of possibility of expected danger is low, the above control can be annoying to the occupant, whereas when the degree is high, the same control is insufficient and unsatisfactory to him. Thus, the above control is not fully effective to warn the occupant of expected danger.
There is also conventionally known an automotive vehicle having a function of storing, upon a collision of the automotive vehicle, the value of acceleration caused by the collision and the collision speed, in order to utilize the stored data in clearing up the cause of the accident, for example.
In the known automotive vehicle, however, it is the value of acceleration caused by the collision and the collision speed that are stored, but not information (parameters) related to the automotive passenger restraint and protection apparatus. Therefore, it is not easy to judge whether the automotive passenger restraint and protection apparatus properly operated upon the collision, and how the occupant behaved just before and/or after the collision, for example.
An automotive passenger restraint and protection apparatus is also known, which is provided with an electric retractor which rotates a reel shaft by means of a driving force of an electric motor to protract and retract a seatbelt.
An example of the automotive passenger restraint and protection apparatus provided with such an electric retractor is disclosed by Japanese Laid-Open Patent Publication (Kokai) No. 59-45240, which is adapted to control the driving of the electric motor based upon an output from a displacement detecting device which detects displacement of the seatbelt in retracting and protracting directions as well as an output from an attaching detecting device which detects attaching of the seatbelt to the occupant""s body.
The electric retractor, however, requires the displacement detecting device which is expensive, and therefore has an increased manufacturing cost and a complicated construction.
Further, the rotation control of the electric motor of the electric retractor is carried out by applying constant voltage of negative and positive signs to the motor to cause normal rotation and reverse rotation of the motor, as disclosed by Japanese Laid-Open Utility Model. Publication (Kokai) No. 61-134464.
According to the known electric retractor, however, since the motor is rotated in the normal direction or in the reverse direction depending upon the application of the constant voltage, there is a possibility that in retracting the seatbelt, the seatbelt is suddenly wound up by the motor so that a tongue of the seatbelt hits against a side window pane.
Another electric retractor is disclosed by Japanese Laid-Open Patent Publication (Kokoku) No. 3-79212, in which a retracting force is stored in a return spring (second retracting force generating device) utilizing the protracting motion of the seatbelt, and when the motor output drops below a predetermined value such that the motor cannot retract the seatbelt, for example, due to failure of an electrical system for driving the motor (first retracting force generating device), or a drop in the motor torque due to a drop in the electromotive force of a battery installed in the automotive vehicle, a rotative force transmission device transmits the retracting force stored in the return spring to a takeup shaft of the seatbelt. This assures retraction of the seatbelt even when the seatbelt cannot be wound up by the motor.
According to this retractor, however, the motor (first retracting force generating device) or the return spring (second retracting force generating device) is selected to retract the seatbelt by the rotative force transmission device, that is, the two devices are not simultaneously used for retraction of the seatbelt. which requires designing each of the motor and the return spring so as to produce a strong retracting force by itself.
Besides, in the retractor, if the retracting force of the motor becomes weakened due to aging change, etc. so that the motor cannot fully retract the seatbelt, the motor is switched to the return spring for retracting the seatbelt. However, in fact the retracting force of the motor is merely weakened but not reduced to zero. Therefore, if the motor is switched to the return spring for retracting the seatbelt, the retracting force remaining in the motor cannot be fully utilized.
An automotive passenger restraint and protection apparatus is also known from Japanese Laid-Open Patent Publication (Kokai) No. 9-82171, which turns on or off a switch for detecting an amount of retraction of a seatbelt on a reel shaft, depending upon the thickness of a portion of the seatbelt wound on the reel shaft, to thereby detect an amount of protracting of the seatbelt or the amount of retraction of the same, to use the detected value in controlling an electric circuit for warning the occupant of failure to fasten the seatbelt or in controlling a seatbelt locking mechanism provided in a seatbelt retractor.
In the seatbelt retraction detecting switch, however, since the amount of protraction or amount of retraction of the seatbelt is detected by turning-on or turning-off of the seatbelt retraction amount detecting switch, only information as to whether the seatbelt has been wound up or pulled out by a predetermined amount or more can be obtained, and a specific value of the protracting amount or retraction amount cannot be obtained.
It is a first object of the invention to provide an automotive passenger restraint and protection apparatus which is capable of providing a comfortable seatbelt attaching environment.
A second object of the invention is to provide an automotive passenger restraint and protection apparatus which permits slow retraction of a seatbelt.
A third object of the invention is to provide an automotive passenger restraint and protection apparatus which is capable of performing accurate fault diagnosis of seatbelt locking means.
A fourth object of the invention is to provide an automotive passenger restraint and protection apparatus which is capable of protecting an occupant in a more reliable manner than in the conventional passenger restraint and protection apparatuses.
A fifth object of the invention is to provide an automotive passenger restraint and protection apparatus which is capable of preventing damage to the seat belt.
A sixth an automotive passenger restraint and protection apparatus which is capable of avoiding occurrence of a fault due to retraction of the seatbelt.
A seventh object of the invention is to provide an automotive passenger restraint and protection apparatus which is capable of giving warning to the occupant in a manner dependent upon the degree of expected danger to thereby fully alert him to the danger.
An eighth object of the invention is to provide an automotive passenger restraint and protection apparatus which is capable of accurately determining the operative state of the apparatus, the state of the occupant, and others upon a collision of the automotive vehicle.
A ninth object of the invention is to provide an automotive passenger restraint and protection apparatus which can be manufactured at reduced costs and can be simplified in construction.
A tenth object of the invention is to provide an automotive passenger restraint and protection apparatus which is capable of quickly and accurately controlling an electric motor for driving the seatbelt.
An eleventh object of the invention is to provide an automotive passenger restraint and protection apparatus which is capable of accurately determining the stoppage of driving of the electric motor irrespective of environmental conditions under which the motor is operated.
A twelfth object of the invention is to provide an automotive passenger restraint and protection apparatus which is capable of accurately determining shifting of the driving force of the electric motor from a present state to a state in which the driving force is progressively decreased.
A thirteenth object of the invention is to provide an automotive passenger restraint and protection apparatus which is capable of fully utilizing the driving force for retraction of the seatbelt.
A fourteenth object of the invention is to provide an automotive passenger restraint and protection apparatus which is capable of accurately performing fault diagnosis of driving means for the seatbelt.
A fifteenth object of the invention is to provide a seatbelt protraction and retraction amount-detecting device which is capable of detecting the amount of protraction and amount of retraction of the seatbelt in a simple manner and with high accuracy.
To attain the first object, according to a first aspect of the present invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising an electric retractor having driving means for retracting and, protracting the seatbelt, control means for controlling the driving means, and detecting means for detecting protraction of the seatbelt by the occupant, wherein when the protraction of the seatbelt is detected by the detecting means, the control means controls the driving means so as to protract the seatbelt.
With the arrangement according to the first aspect, when protraction of the seatbelt is detected by the protraction detecting means, the driving means is controlled to protract the seatbelt. As a result, a large force as required in the conventional automotive passenger restraint and protection apparatus is not required for protracting the seatbelt, and therefore even a weak occupant who has degraded physical ability such as an advanced-age occupant can easily mount the seatbelt onto his body.
To attain the second object, according to a second aspect of the invention, the automotive passenger restraint and protection apparatus according to the first aspect includes a power supply, and supply means for supplying supply voltage from the power supply to the driving means, and the control means controls driving operation of the driving means by controlling magnitude of,the supply voltage or degree of modulation of pulse width thereof.
With the arrangement. according to the second aspect, the magnitude of the supply voltage supplied to the driving means or the degree of modulation of pulse width thereof is controlled to control the driving operation of the driving means. As a result, the seatbelt can be slowly retracted, and therefore it is possible to eliminate the disadvantage with the conventional apparatus that since supply voltage of a predetermined value continues to be applied to the driving means, in storing the seatbelt, the seatbelt is suddenly retracted by the driving means, which can result in that the seatbelt tongue is hit against the side window pane.
To attain the first object, according to a third aspect of the invention, the automotive passenger restraint and protection apparatus according to the first aspect includes seatbelt locking means for locking the seatbelt from being protracted when the seatbelt is protracted at a predetermined or high degree of acceleration, and the control means controls the driving means to thereby control speed of protraction or retraction of the seatbelt at least one of conditions is satisfied that the driving means stops retracting driving of the seatbelt, the driving means starts protracting driving of the seatbelt from a stopped state of the seatbelt, and the driving means shifts from the retracting driving of the seatbelt to protracting driving of the seatbelt.
With the arrangement according to the third aspect, the speed of protraction or retraction of the seatbelt is controlled when the protraction or retraction of the seatbelt is carried out by the driving means. As a result, the seatbelt can never be locked during protraction, and therefore the occupant can be released from a state where he receives a large force of oppression, providing a comfortable seatbelt attaching environment.
To attain the first and fourth objects, according to a fourth aspect of the invention, the automotive passenger restraint and protection apparatus according to the first aspect includes seatbelt locking means for locking the seatbelt from being protracted when the seatbelt is protracted at a predetermined or high degree of acceleration, and wherein when the seatbelt is locked from being protected by the seatbelt locking means, the control means controls the driving means to retract the seatbelt to a limit thereof and then protract the seatbelt for a predetermined time period.
With the arrangement according to the fourth aspect, when the seatbelt is locked from being protected, the driving means is controlled to retract the seatbelt to a limit thereof and then protract the seatbelt for a predetermined time period. As a result, the seatbelt can be given a predetermined amount of looseness without fail, whereby a comfortable seatbelt attaching environment is provided.
To attain the first and fourth objects, according to a fifth aspect of the invention, in the automotive passenger restraint and protection apparatus according to the fourth aspect, when the seatbelt has been retracted to the limit thereof by the driving means, the control means controls the driving means to protract the seatbelt by a first predetermined amount and then again retract the seatbelt by a second predetermined amount smaller than the first predetermined amount.
With the arrangement according to the fifth aspect, after protraction of the seatbelt which is a condition for locking of the seatbelt, the seatbelt is retracted. As a result, the locking of the seatbelt is released without fail. Further, a predetermined amount of looseness corresponding to the difference between the first and second predetermined amounts is given to the seatbelt or the occupant, whereby a comfortable seatbelt attaching environment is provided and the occupant can be properly protected.
To attain the third object, according to a sixth aspect of the invention, the automotive passenger restraint and protection apparatus according to the fourth aspect includes acceleration detecting means for detecting acceleration of protraction of the seatbelt when the seatbelt is protracted, and abnormality diagnosis means for carrying out diagnosis as to abnormality of the seatbelt locking means by making a determination as to whether the seatbelt locking means has operated in response to the acceleration detected by the acceleration detecting means, and determining abnormality of the seatbelt locking means, based upon results of the determination.
With the arrangement according to the sixth aspect, abnormality of the seatbelt locking means can be determined with accuracy.
To attain the first object, according to a seventh aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising an electric retractor having driving means for retracting and protracting the seatbelt control means for controlling the driving means, seatbelt attaching detecting means for detecting whether the seatbelt is attached to the occupant or disconnected from the occupant, and retraction limit detecting means for detecting whether the seatbelt has been retracted to a limit thereof, wherein the control means controls the driving means in a manner such that when the seatbelt attaching detecting means detects that the seatbelt has become attached to the occupant from a state in which it is disconnected from the occupant, the seatbelt is retracted, and when the retraction limit detecting means subsequently detects that the seatbelt has been retracted to the limit thereof, the seatbelt is stopped from being retracted, and then the seatbelt is protracted for a predetermined time period.
According to the seventh aspect. when the limit of retraction of the seatbelt has been detected, the retraction of the seatbelt is stopped from being retracted by the driving means, and then the seatbelt is protracted for a predetermined time period by the driving means. As a result, the seatbelt is give a predetermined amount of looseness without fail, eliminating the disadvantage with the conventional automotive passenger restraint and protection apparatus that the occupant is given a feeling of oppression by the seatbelt mounted on his body and feels uncomfortable, whereby a comfortable seatbelt attaching environment is provided.
To attain the fifth object, according to an eight aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising an electric retractor having driving means for retracting and protracting the seatbelt, control means for controlling the driving means, seatbelt attaching detecting means for detecting whether the seatbelt is attached to the occupant or disconnected from the occupant, retraction limit detecting means for detecting whether the seatbelt has been retracted to a limit thereof, wherein the control means controls the driving means in a manner such that when the seatbelt attaching detecting means detects that the seatbelt has become attached to the occupant from a state in which it is disconnected from the occupant, the seatbelt is retracted, and when the retraction limit detecting means subsequently detects that the seatbelt has been retracted to the limit thereof, the seatbelt is stopped from being retracted.
With the arrangement according to the eighth aspect, after the attaching of the seatbelt is released, the seatbelt is retracted without fail, it can be prevented that the tongue of the seatbelt is caught in the door.
To attain the fourth object, according to a ninth aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising, an electric retractor having driving means for retracting and protracting the seatbelt, control means for controlling the driving means, seatbelt protraction detecting means for detecting protraction of the seatbelt by the occupant, seatbelt attaching detecting means for detecting attaching of the seatbelt to the occupant or disconnection of the seatbelt from the occupant, bias force-imparting means for imparting a bias force to the seatbelt in a retracting direction, seatbelt retraction detecting means for detecting retraction of the seatbelt by the bias force-imparting means, and retraction limit detecting means for detecting whether the seatbelt has been retracted to a limit thereof, wherein the control means controls the driving means in a manner such that when said seatbelt protraction means detects the protraction of the seatbelt by the occupant after the seatbelt attaching detecting means detects the attaching of the seatbelt to the occupant, the seatbelt is protracted, when the seatbelt retraction detecting means subsequently detects the retraction of the seatbelt by the bias force-imparting means, the seatbelt is retracted, and when the retraction limit detecting means detects that the seatbelt has been retracted to the limit thereof, the seatbelt is stopped from being retracted and then protracted for a predetermined time period.
With the arrangement according to the ninth aspect, even when the occupant moves after attaching the seatbelt to his body to protract the seatbelt, the seatbelt is given a predetermined amount of looseness without fail, whereby a comfortable seatbelt attaching environment is provided and the occupant can be properly protected.
To attain the fourth object, according to a tenth aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising an electric retractor having driving means for retracting and protracting the seatbelt, control means for controlling the driving means, seatbelt protraction detecting means for detecting protraction of the seatbelt; and seatbelt attaching detecting means for detecting whether the seatbelt is attached to the occupant or disconnected from the occupant, wherein the control means controls the driving means in a manner such that when the seatbelt attaching detecting means detects that the seatbelt has become attached to the occupant from a state in which it is disconnected from the occupant or the seatbelt is held attached to the occupant, and then the seatbelt protraction detecting means detects the protraction of the seatbelt, followed by the seatbelt becoming possible to retract, the seatbelt is retracted to a limit thereof and then protracted for a first predetermined time period, and then, after lapse of a second predetermined time period, the seatbelt is retracted to the limit thereof, the protraction of the seatbelt for the first predetermined time period and the retraction and protraction after the lapse of the second predetermined time period being carried out at least one time.
With the arrangement according to the tenth aspect, an extra amount of looseness of the seatbelt is removed and an appropriate amount of looseness is given to the occupant. Then, even if the seatbelt is protracted by movement of the occupant during the subsequent second time period, an extra amount of looseness of the seatbelt is removed at least one time so as to given an appropriate amount of looseness to the occupant. As a result, the occupant is given an appropriate amount of looseness and can also be properly protected.
To attain the sixth object, according to an eleventh aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising an electric retractor having driving means for retracting and protracting the seatbelt, control means for controlling the driving means, and retraction failure detecting means for detecting retraction failure of the seatbelt, wherein the control means controls the driving means to stop retracting the seatbelt when the retraction failure detecting means detects the retraction failure of the seatbelt.
With the arrangement according to the eleventh aspect, when retraction failure of the seatbelt is detected, the driving means is controlled to stop retracting the seatbelt. As a result, the occurrence of a fault due to the retraction of the seatbelt can be prevented.
To attain the fourth object, according to a twelfth aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising an electric retractor having driving means for retracting and protracting the seatbelt, control means for controlling the driving means, and doze indication detecting means for detecting an indication of doze of the occupant during driving of the automotive vehicle, wherein the control means controls the driving means to carry out alternately retraction and protraction of the seatbelt for a predetermined time period when the doze indication detecting means detects the indication of doze of the occupant during driving of the automotive vehicle.
With the arrangement according to the twelfth aspect, when an indication of doze of the occupant during driving of the automotive vehicle is detected, the driving means is controlled to carry out alternately retraction and protraction of the seatbelt for a predetermined time period to warn the occupant. As a result, the occupant can be warned of danger of doze while driving the automotive vehicle and therefore can be surely protected.
To attain the fourth object, according to a thirteenth aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising an electric retractor having driving means for retracting and protracting the seatbelt, control means for controlling the driving means, and rough road traveling notifying means for notifying the control means of traveling of the automotive vehicle on a rough road, wherein the control means is responsive to notifying from the rough road traveling notifying means of traveling of the automotive vehicle on the rough road, for controlling the driving means to retract the seatbelt.
With the arrangement according to the thirteenth aspect, when the rough road traveling notifying means notifies that the automotive vehicle is traveling on a rough road, the driving means is controlled to retract the seatbelt. As a result, the occupant can be positively protected even during traveling of the automotive vehicle on a rough road.
To attain the fourth object, according to a fourteenth aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising an electric retractor having driving means for retracting and protracting the seatbelt, control means for controlling the driving means, and doze prevention commanding means for commanding the control means to prevent dozing of the occupant during driving the automotive vehicle, wherein the control means is responsive to commanding from the doze prevention commanding means to prevent dozing of the occupant during driving of the automotive vehicle, for controlling the driving means to carry out alternately retraction and protraction of the seatbelt at irregular time intervals.
With the arrangement according to the fourteenth aspect, when a command is issued from the doze prevention commanding means to prevent dozing of the occupant during driving the automotive vehicle, the driving means is controlled to carry out alternately retraction and protraction of the seatbelt at irregular time intervals. As a result, the occupant can be prevented from dozing while driving the automotive vehicle and therefore can be surely protected.
To attain the first object, according to a fifteenth aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising an electric retractor having driving means for retracting and protracting the seatbelt, control means for controlling the driving means, seatbelt attaching detecting means for detecting attaching of the seatbelt to the occupant or disconnection of the seatbelt from the occupant, and protraction stoppage detecting means for detecting stoppage of protraction of the seatbelt, wherein when the protraction stoppage detecting means detects the stoppage of protraction of the seatbelt, the control means causes the seatbelt attaching detecting means to repeatedly carry out detection of attaching of the seatbelt to the occupant or disconnection of the seatbelt from the occupant, causes the protraction stoppage detecting means to repeatedly carry out detection of stoppage of protraction of the seatbelt, and when the stoppage of protraction of the seatbelt is detected by the protraction stoppage detecting means while the attaching of the seatbelt to the occupant is not detected by the seatbelt attaching detecting means, the control means controls the driving means to retract the seatbelt.
With the arrangement according to the fifteenth aspect, when the occupant has protracted the seatbelt without the intention of attaching it to his body, the seatbelt can be quickly retracted, whereby a comfortable seatbelt attaching environment is provided.
To attain the fourth object, according to a sixteenth aspect of the invention, the automotive passenger restraint and protection apparatus according to the fifteenth aspect includes vehicle speed detecting means for detecting traveling speed of the automotive vehicle, and wherein the control means inhibits the driving means from retracting the seatbelt if the traveling speed of the automotive vehicle detected by the vehicle speed detecting means is lower than a predetermined value when the stoppage of protraction of the seatbelt is detected by the protraction stoppage detecting means after the attaching of the seatbelt to the occupant is detected by the seatbelt attaching detecting means.
With the arrangement according to the sixteenth aspect, when the occupant is slowing reversing the automotive vehicle for parking, the seatbelt is inhibited from being retracted. As a result, it can be prevented that the seatbelt is retracted to the limit while the occupant is looking backward, to thereby properly restrain the occupant to protect him. Further, when protraction of the seatbelt has been carried out due to movement of the occupant with the seatbelt mounted on his body, which takes place, for example, when the occupant once stops the vehicle and then slouches to look right and left ways for safety, retraction of the seatbelt is inhibited. As a result, it is possible to prevent the occupant from being given a feeling of unnaturalness while looking right and left ways for safety to thereby assure the safety ascertainment.
To attain the fifth object, according to a seventeenth aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle having doors, and a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising an electric retractor having driving means for retracting and protracting the seatbelt, control means for controlling the driving means, and door opening/closing detecting means for detecting opening and closing of a predetermined one of the doors, wherein when the door opening/closing means detects the opening of the predetermined one of the doors, the control means controls the driving means to carry out retraction of the seatbelt at a higher speed than when the door opening/closing means detects the closing of the predetermined one of the doors.
With the arrangement according to the seventeenth aspect, when it is detected that the door is open, the driving means is controlled to carry out retraction of the seatbelt at a higher speed than when the door is closed. As a result, it is possible to prevent the seatbelt from being caught in the door.
To attain the first object, according to an eighteenth aspect of the invention, the automotive passenger restraint and protection apparatus according to the seventeenth aspect includes vehicle reverse detecting means for detecting a reverse of the automotive vehicle, and seatbelt attaching detecting means for detecting attaching of the seatbelt to the occupant or disconnection of the seatbelt from the occupant, and wherein the control means inhibits the driving means from retracting the seatbelt when the attaching of the seatbelt to the occupant is detected by the seatbelt attaching detecting means, the opening of the predetermined one of the doors is detected by the door opening/closing detecting means and at the same time the reverse of the automotive vehicle is detected by the vehicle reverse detecting means.
With the arrangement according to the eighteenth aspect, when it is detected that the seatbelt is attached to the occupant, the door is open, and at the same time the automotive vehicle is reversing, the driving means is controlled to inhibit retraction of the seatbelt. As a result, the seatbelt is not retracted when the occupant is reversing the automotive vehicle for parking with the door being open, thereby preventing the occupant from being given a feeling of unnaturalness, and providing a comfortable seatbelt attaching environment.
To attain the fourth object, according to a nineteenth aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising an electric retractor having driving means for retracting and protracting the seatbelt, control means for controlling the driving means, collision danger detecting means for detecting danger of collision of the automotive vehicle, wherein the control means controls the driving means to carry out alternately retraction and protraction of the seatbelt for a predetermined time period, based upon results of detection of the danger of collision by the collision danger detecting means when the collision danger detecting means detects the danger of collision of the automotive vehicle.
With the arrangement according to the nineteenth aspect, when danger of collision of the automotive vehicle is detected, the driving means is controlled to carry out alternately retraction and protraction of the seatbelt for a predetermined time period, based upon results of detection by the collision danger detecting means. As a result, the occupant can be given a warning of danger of collision of the automotive vehicle and hence can be positively protected in the event of a collision of the automotive vehicle.
To attain the seventh object, according to a twentieth aspect of the invention, in the automotive passenger restraint and protection apparatus according to the nineteenth aspect, the control means controls a force of the driving means for retracting the seatbelt and a force of the driving means for protracting the seatbelt by controlling the driving means based upon the results of detection of the danger of collision by the collision danger detecting means.
With the arrangement according to the twentieth aspect, the seatbelt retracting force and the seatbelt protracting force are controlled based upon the results of detection of the danger of collision by the collision danger detecting means. As a result, the occupant can be given a warning in a manner dependent upon the degree of danger and can therefore be fully alerted to the danger of collision.
To attain the seventh object, according to a twenty-first aspect of the invention, in the automotive passenger restraint and protection apparatus according to the nineteenth aspect, the control means controls a period of retraction of the seatbelt by the driving means and a period of protraction of the seatbelt by the driving means by controlling the driving means based upon the results of detection of the danger of collision by the collision danger detecting means.
With the arrangement according to the twenty-first aspect, the period of retraction and period of protraction by the driving means are controlled based upon the results of detection of the danger of collision by the collision danger detecting means. As a result, the occupant can be given a warning in a manner dependent upon the degree of danger and can therefore be fully alerted to the danger of collision.
To attain the eighth object, according to a twenty-second aspect of the invention, the automotive passenger restraint and protection apparatus according to the nineteenth aspect includes storage means for storing a state of use of the seatbelt, and wherein the control means stores at least one of the state of use of the seatbelt before a collision of the automotive vehicle and the state of use of the seatbelt after the collision of the automotive vehicle, when the collision danger detecting means detects the danger of collision of the automotive vehicle.
With the arrangement according to the twenty-second aspect, when danger of collision of the automotive vehicle is detected, a state of use of the seatbelt before and/or after a collision of the automotive vehicle is stored in the storage means. As a result, by reading out contents stored in the storage means after a collision of the automotive vehicle, it is possible to accurately determinate the operative state of the automotive passenger restraint and protection apparatus and the occupant state in the event of a collision of the vehicle or a like accident, for use of the same in investigating the cause of the accident.
Preferably, the automotive passenger restraint and protection apparatus according to the according to the twenty-second aspect includes a power supply, and auxiliary power supply means for supplying power from the power supply to the control means for a predetermined time period after a collision of the automotive vehicle, and wherein the storage means comprises a non-volatile ROM.
With this arrangement, in addition to the possibility of accurate determination of the operative state of the automotive passenger restraint and protection apparatus and the occupant state in the event of a collision of the vehicle or a like accident, power from the power supply can be supplied to the control means even after a collision of the automotive vehicle, whereby the operative state of the automotive passenger restraint and protection apparatus and the occupant state in the event of a collision of the vehicle or a like accident can be stored for use in investigating the cause of the accident.
To attain the fourth object, according to a twenty-third aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle having an airbag, the apparatus having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising an electric retractor having seatbelt driving means for retracting and protracting the seatbelt, airbag driving means for causing expansion of the airbag to restrain the occupant, a pretensioner for rapidly retracting the seatbelt to restrain the occupant, speed detecting means for detecting a speed of protraction of the seatbelt, and control means for controlling at least one of actuation time or expansion pressure of the airbag by the airbag driving means, actuation time of the pretensioner, a force of the pretensioner for retracting the seatbelt, and a force of the seatbelt driving means for retracting the seatbelt, based upon the speed of protraction of the seatbelt detected by the speed detecting means.
With the arrangement according to the twenty-third aspect, at least one of the actuation time or expansion pressure of the airbag by the airbag driving means, the actuation time of the pretensioner, the force of the pretensioner for retracting the seatbelt, the force of the pretensioner for retracting the seatbelt, and the force of the seatbelt driving means for retracting the seatbelt is controlled based upon the speed of protraction of the seatbelt detected by the speed detecting means. As a result, the occupant can be properly protected upon a collision of the automotive vehicle.
Preferably, in the automotive passenger restraint and protection apparatus according to the twenty-third aspect, the control means controls the airbag driving means to shorten the actuation time of the airbag when the speed of protraction of the seatbelt detected by the speed detecting means is higher than a predetermined value, and prolong the actuation time of the airbag when the detected speed of protraction of the seatbelt is lower than the predetermined value.
With this arrangement, when the detected speed of protraction of the seatbelt is higher than a predetermined value, the actuation time of the airbag is shortened, while when the detected speed of protraction of the seatbelt is lower than the predetermined value, the actuation time of the airbag is prolonged. Therefore, when the protracting speed of the seatbelt is high such as upon a strong collision of the automotive vehicle, the actuation time of the airbag is set to a relatively short value such that the airbag quickly operates, while when the protracting speed of the seatbelt is low such as upon a weak collision of the automotive vehicle, the actuation time of the airbag is set to a relatively long value such that the airbag slowly operates. As a result, the occupant can be properly protected in the event of a collision of the automotive vehicle.
Also preferably, in the automotive passenger restraint and protection apparatus according to the twenty-third aspect, the control means controls the airbag driving means to decrease the expansion pressure of the airbag when the speed of protraction of the seatbelt detected by the speed detecting means is higher than a predetermined value, and increase the expansion pressure of the airbag when the detected speed of protraction of the seatbelt is lower than the predetermined value.
With this arrangement, when the protracting speed of the seatbelt is higher than a predetermined, the expansion pressure of the airbag is set to a relatively small value so as to reduce impact applied to the occupant, to thereby more properly protect the occupant in the event of a strong collision of the automotive vehicle. On the other hand, when the protracting speed of the seatbelt is lower than the predetermined value, the expansion pressure of the airbag is set to a relatively large value, i.e. a moderate expansion pressure to thereby more properly protect the occupant in the event of a weak collision of the automotive vehicle.
Preferably, in the automotive passenger restraint and protection apparatus according to the twenty-third aspect, the control means controls the pretensioner to shorten the actuation time of the pretensioner when the speed of protraction of the seatbelt detected by the speed detecting means is higher than a predetermined value, and prolong the actuation time of the pretensioner when the detected speed of protraction of the seatbelt is lower than the predetermined value.
With this arrangement, when the protracting speed of the seatbelt is higher than a predetermined value, the actuation time of the pretensioner is set to a relatively short value so as to quickly actuate the pretensioner, to thereby more properly protect the occupant in the event of a strong collision of the automotive vehicle. On the other hand, when the protracting speed of the seatbelt is lower than the predetermined value, the actuation time of the pretensioner is set to a relatively long value so as to slowly actuate the pretensioner, to thereby more properly protect the occupant in the event of a weak collision of the automotive vehicle.
Also preferably, in the automotive passenger restraint and protection apparatus according to the twenty-third aspect, the control means controls the pretensioner to decrease the force of the pretensioner for retracting the seatbelt when the speed of protraction of the seatbelt detected by the speed detecting means is higher than a predetermined value, and increase the force of the pretensioner for retracting the seatbelt when the detected speed of protraction of the seatbelt is lower than the predetermined value.
With this arrangement, when the protracting speed of the seatbelt is higher than the predetermined value, the seatbelt retracting force of the pretensioner is set to a relatively small value so as to reduce impact applied to the occupant, to thereby more properly protect the occupant in the event of a strong collision of the automotive vehicle. On the other hand, when the protracting speed of the seatbelt is lower than the predetermined value, the seatbelt retracting force of the pretensioner is set to a relatively large value so as to apply an appropriate magnitude of impart to the occupant, to thereby more properly protect the occupant in the event of a weak collision of the automotive vehicle.
Preferably, in the automotive passenger restraint and protection apparatus according to the twenty-third aspect, the control means controls the seatbelt driving means to increase the force of the seatbelt driving means for retracting the seatbelt when the speed of protraction of the seatbelt detected by the speed detecting means is higher than a predetermined value, and decrease the force of the seatbelt driving means for retracting the seatbelt when the detected speed of protraction of the seatbelt is lower than the predetermined value.
With this arrangement, when the protracting speed of the seatbelt is higher than the predetermined value, the force of the electric retractor for retracting the seatbelt is set to a relatively large value such that protraction of the seatbelt requires a relatively large force, while when the protracting speed of the seatbelt is lower than the predetermined value, the force of the electric retractor for retracting the seatbelt is set to a relatively small value such that protraction of the seatbelt requires a relatively small force. Thus, the protraction of the seatbelt is controlled so as to absorb impact applied to the occupant in the event of a collision of the automotive vehicle.
To attain the ninth object, according to a twenty-fourth aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising a reel shaft having the seatbelt wound thereon, a motor for rotating the reel shaft in a direction of protracting or retracting the seatbelt, change amount detecting means for detecting an amount of change in at least one of terminal voltage across the motor and current flowing to the motor, seatbelt attaching detecting means for detecting attaching of the seatbelt to the occupant or disconnection of the seatbelt from the occupant, and control means for controlling the motor, based upon results of detections by the change amount detecting means and the seatbelt attaching detecting means.
With the arrangement according to the twenty-fourth aspect, the motor is controlled based upon results of detections of an amount of change in at least one of terminal voltage across the motor and current flowing to the motor and attaching or disconnection of the seatbelt to or from the occupant. As a result, an expensive displacement detecting device is not required for controlling the motor, and therefore, the present apparatus can be manufactured at a reduced cost and simplified in construction.
To attain the tenth object, according to a twenty-fifth aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising PWM signal generating means for generating a PWM signal, a motor for retracting and protracting the seatbelt, the motor having operation thereof controlled by the PWM signal generated by the PWM signal generating means, and determining means for detecting at least one of current flowing to the motor and terminal voltage across the motor and for determining a state of the operation of the motor, based upon the detected at least one of the current and the terminal voltage, the determining means having low-pass filter means having a predetermined cutoff frequency lower than a frequency of the PWM signal, wherein the determining means causes the filter means to reduce higher frequency components than the predetermined cutoff frequency, contained in the at least one of the current and the terminal voltage, and determines the state of the operation of the motor, based upon the at least one of the current and the terminal voltage having the higher frequency components reduced.
With the arrangement according to the twenty-fifth aspect, the low-pass filter means having a predetermined cutoff frequency lower than a frequency of the PWM signal reduces higher frequency components than the predetermined cutoff frequency, contained in the at least one of current flowing to the motor and terminal voltage across the motor, and the state of the operation of the motor is determined, based upon the at least one of the current and the terminal voltage having the higher frequency components reduced. As a result, the burden on the determining means (MPU) is greatly reduced as compared with the conventional apparatus, making it possible to quickly control the motor by the use of an inexpensive MPU.
To attain the eleventh object, according to a twenty-sixth aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising a reel shaft having the seatbelt wound thereon, a motor for rotating the reel shaft in a direction of protracting or retracting the seatbelt, motor stoppage detecting means for detecting stoppage of the motor, based upon results of a comparison between a value of current flowing to the motor and a threshold value, and control means for controlling the threshold value according to environmental conditions under which the motor is operated.
With the arrangement according to the twenty sixth aspect, the threshold value of current flowing to the motor for detecting stoppage of the motor is controlled according to environmental conditions under which the motor is operated. As a result, the stoppage of the motor can be detected with accuracy irrespective of the environmental conditions under which the motor is operated.
Preferably, in the automotive passenger restraint and protection apparatus according to the twenty-sixth aspect, the threshold value is set to a value of the current flowing to the motor to be assumed when the motor has shifted from a rotatively driven state to a stopped state, the threshold value being calculated based upon supply voltage applied to the motor. As a result, the stoppage of the motor can be detected with higher accuracy irrespective of the environmental conditions under which the motor is operated.
To attain the twelfth object, according to a twenty-seventh aspect of the invention, in the automotive passenger restraint and protection apparatus according to the twenty-sixth aspect, the threshold value is set to a value of the current flowing to the motor to be assumed when a driving force of the motor is to be progressively decreased from a rotatively driven state, the threshold value being calculated based upon supply voltage applied to the motor, the control means progressively decreasing the driving force of the motor from a current value, based upon the results of the comparison between the value of the current flowing to the motor and the threshold value.
With the arrangement according to the twenty-seventh aspect, it is possible to accurately determine timing for progressively decreasing the driving force of the motor from a current value irrespective of the environmental conditions under which the motor is operated.
To attain the thirteenth object, according to a twenty-eighth aspect of the invention, there is provided an automotive passenger restraint and protection apparatus for an automotive vehicle, having a seatbelt, for restraining an occupant of the automotive vehicle by the seatbelt to protect the occupant, comprising a reel shaft having the seatbelt wound thereon, a plurality of driving means for rotatively driving the reel shaft, and driving force ratio determining means for determining a ratio of driving force between the plurality of driving means.
With the arrangement according to the twenty-eighth aspect, the ratio of driving force between the plurality of driving means is variably set, for example, such that when one of the plurality of driving means has a degraded driving force, the ratio of driving force of the other driving means is set to an increased value. As a result, the driving force of the one driving means can be utilized to the fullest extent, to thereby enable exhibiting the driving force for retracting the seatbelt to the maximum possible extent.
Preferably, in the automotive passenger restraint and protection apparatus according to the twenty-eighth aspect, the driving force ratio determining means includes pulse width adjusting means for adjusting a PWM signal delivered to the plurality of driving means, the ratio of driving force being determined by the pulse width adjusting means.
With this arrangement, the ratio of driving force between the plurality of driving means can be accurately determined in an electrical manner, while exhibiting the driving force for retracting the seatbelt to the maximum possible extent.
To attain the fourteenth object, according to a twenty-ninth aspect of the invention, the automotive passenger restraint and protection apparatus according to the twenty-eighth aspect includes comparison means for driving one of the plurality of driving means and other driving means thereof with an equal driving force, and for comparing at least one of terminal voltage and pulsating components thereof between the one driving means and the other driving means, and abnormality diagnosis means for carrying out abnormality diagnosis based upon results of comparison by the comparison means.
With the arrangement according to the twenty-ninth aspect, one of the plurality of driving means and other driving means thereof are driven with the same driving force, and at least one of the terminal voltage and pulsating components thereof is compared between the one driving means and the other driving means, to carry out abnormality diagnosis based upon results of the comparison. As a result, abnormality of the driving means can be carried out in an electrical manner with accuracy.
Preferably, in the automotive passenger restraint and protection apparatus according to the twenty-ninth aspect, the abnormality diagnosis means comprises determining means for driving the one driving means with a predetermined driving force and for determining whether the terminal voltage across the other driving means or the pulsating components thereof show a value corresponding to the predetermined driving force.
With this arrangement, the one driving means is driven with a predetermined driving force, and it is determined whether the terminal voltage across the other driving means or the pulsating components thereof show a value corresponding to the predetermined driving force. As a result, abnormality of the driving means can be carried out in an electrical manner with higher accuracy.
To attain the fifteenth object, according to a thirtieth aspect of the invention, there is provided a seatbelt protraction and retraction amount-detecting device for an automotive passenger restraint and protection apparatus having a seatbelt, and a motor for rotating protracting or retracting the seatbelt, comprising motor rotational direction detecting means for detecting rotational direction of the motor, voltage detecting means for detecting terminal voltage across the motor, and protraction/retraction amount calculating means for calculating an amount of protraction or an amount of retraction of the seatbelt, based upon at least one of a number of times pulsating components of the terminal voltage detected by the voltage detecting means rises above a first predetermined value from a value below the first predetermined value, a number of times the pulsating components drops below a second predetermined value from a value above the second predetermined value, a frequency component obtained by frequency analysis of the pulsating components, and results of time integration of the detected terminal voltage, and the rotational direction of the motor detected by the motor rotational direction detecting means.
With the arrangement according to the thirtieth aspect, the rotational direction of the motor is detected, and the amount of protraction or the amount of retraction of the seatbelt is calculated, based upon at least one of a number of times pulsating components of the terminal voltage across the motor rises above a first predetermined value from a value below the first predetermined value, a number of times the pulsating components drops below a second predetermined value from a value above the second predetermined value, a frequency component obtained by frequency analysis of the pulsating components, and results of time integration of the detected terminal voltage, and the detected rotational direction of the motor. As a result, the amount of protraction or the amount of retraction of the seatbelt can be obtained in a simple manner and with high accuracy.
The above and other objects, features, and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.